JP5670553B2 - System and method for transporting power under seawater and providing fiber optic communications - Google Patents

Description

  The present invention relates to submarine power transportation and submarine communication.

  For some underwater activities or applications, underwater equipment is used at various distances, where such equipment typically requires the availability of communication to and from the equipment along with the supply of power. And

  Some examples of such activities or applications are found in the field of the oil and gas industry, for example, in scientific research on seismic detection, deep sea detection where a platform or other equipment is provided with long-distance underwater equipment.

  Submarine communication is typically based on the use of optical cables with optical fibers. Such a cable connects a first terminal to a second terminal, and possibly more terminals, such that at least a portion of the cable is placed under sea water. Communication between the two. Terminals may be located at very long distances, such as the distance between continents. In addition to carrying data for communication, such cables typically can carry power to power equipment that can be located at an intermediate distance between the two end stations.

  In typical submarine communications, power is supplied with a DC voltage of approximately 10 KV to reduce or minimize the effects of losses incurred in the cable due to attenuation through the distance between the power source and the equipment receiving it. Supplied using.

  Unlike submarine communication systems, underwater activities or applications such as those described above typically use electrical cabling, and the voltage used to supply power is typically the use of optical cables. Much lower than the voltage used for power supply in submarine communication networks. Such a voltage is typically provided using AC power transport. However, the efficiency of alternating current transmission typically decreases rapidly with distance due to the capacitive effect of the cable, which creates ground leakage current that typically increases with cable length. Direct current transmission is typically much less efficient from such limitations, so it is much more efficient and is particularly suitable for long distances (hundreds of kilometers or more).

  Furthermore, the known solutions have the weakness of limitations in coverage with respect to the number of places to provide services or with respect to the reach of the service over a limited distance.

  With regard to communication availability, typically the capabilities of the system are relatively limited. Some of such systems can provide data transfer at relatively low bit rates, typically on the order of several kilobits to tens of kilobits.

  More recently, however, systems of the type described above typically provide higher capacity for communication using more bandwidth, while at the same time providing a higher level of reliability and cost effectiveness compared to previous systems. There is a tendency to demand. Users of such systems, for example oil and gas operators or suppliers, typically need the possibility to operate, monitor and control their offshore facilities more efficiently.

  In addition, such systems are often installed in seawater, typically in the deep water where it is difficult to have regular access, so a fairly long operational “lifetime” of approximately 25 years. Is required. Therefore, the reliability and robustness of such systems is also very important.

  Several attempts have been made to provide a system that enables communication and energy transport using conventional submarine communication cables that improves the overall performance of the system compared to the known systems described above. Are known.

US Pat. No. 6,987,902

  However, in terms of powering the entire network, such a system can be made robust so that if a failure occurs in a network element, the remaining elements can maintain their operational function as much as possible. It is still desirable.

  The solution proposed here is based on the use of fiber optic communication from one or two end stations to a plurality of distributed locations located on the seabed, preferably covering a large area.

  Thus, some embodiments include one or more end stations that may be stations located on land, or fixed or floating at sea level, and at least one branch unit. And a network for transporting communication and power, comprising: a network between the terminal station and the branch unit; and between the branch unit and the submarine node. A trunk cable for enabling optical and electrical connections between the submarine nodes, wherein the submarine node is configured to receive a plurality of optical wavelengths and provide at least one optical wavelength at an output, Configured to convert one DC voltage to a second DC voltage provided at the output, the first voltage is higher than the second voltage, and the network is trunked A first power source connected to the first cable head of the cable and at least a second power source connected to the second cable head of the trunk cable, wherein the first power source and at least the second power source are normal or Features a network configured to provide at least a minimum amount of current in the network individually or in combination under fault conditions.

  According to some particular embodiments, the network comprises internet protocol switching means configured to implement an internet protocol application at the output of the submarine node.

  According to some particular embodiments, the network is a ring network.

  According to some particular embodiments, the network further comprises at least one pseudo load configured to allow current circulation.

  According to some particular embodiments, the first power source is configured to provide direct current power to the first cable head such that the loop is closed between the first power source and the ocean ground. At least the second power supply is connected in parallel with the pseudo load in the standby mode.

  According to some particular embodiments, the first power source and at least the second power source are configured to provide power, the first power source is configured to control the voltage, and at least the second power source Is set to control the current on the main line.

  According to some particular embodiments, the first power source is configured to supply power to the first cable head of the trunk cable, and the second power source supplies power to the second cable head of the trunk cable. Supply, the pseudo load is disconnected, and the resistive load is connected at a node close to the fault location in the network to ensure the presence of current in the submarine node.

  According to some specific embodiments, the network is powered so that if a trunk cable fails, the network not only restores the direct current on the trunk, but also allows communication within the network. A third power source configured to provide

  According to some particular embodiments, the network sets the current demand and the voltage demand to the first power source and at least the second power source so as to keep the current equal at at least one node in the network. A management system configured as described above.

  According to some specific embodiments, the submarine node is configured to stop converting the mains voltage from the first voltage value to the second voltage value if a failure occurs in the branch unit. The

  According to some particular embodiments, the submarine node is configured to stop the conversion operation when the mains voltage falls below a predetermined threshold.

Some embodiments include one or more end stations, which may be stations located on land, or fixed or floating at sea level, and at least one branching unit; A method for transporting communication and power in a network comprising at least one submarine node connected to a branch unit, wherein the network is between a terminal station and a branch unit and between the branch unit and the submarine node. Further comprising a trunk cable for enabling optical and electrical connection between
-Receiving a plurality of light wavelengths at a submarine node and providing at least one light wavelength at an output;
Converting the first DC voltage received from the terminal station into a second DC voltage provided at the output at the submarine node, the first voltage being higher than the second voltage; ,
The network comprises a first power source connected to the first cable head of the trunk cable and at least a second power source connected to the second cable head of the trunk cable, the first power source and the at least second The power supply is characterized by a method of supplying at least a minimum amount of current in the network, individually or in combination, under normal or fault conditions.

  According to some specific embodiments, the submarine node obtains multiple optical wavelengths and filters the wavelengths for use at the submarine node, or the submarine node adds at least one wavelength to the trunk cable.

  According to some particular embodiments, the network further comprises a pseudo load, closing the switch to the second cable head while the pseudo load is still switched to the first cable head; After the switch to the cable head is performed, a pseudo load is applied from the first cable head to the second cable so that the switch is performed at nominal voltage during operation by opening a switch to the first cable head. Switching to the head.

According to some specific embodiments, if the current in the network increases, the following is performed:
-Reducing the voltage available on the mains cable to a threshold intermediate value;
-Stopping the voltage conversion at the submarine node;
Supplying a current lower than the increased current which allows one or more branch units to be switched off safely.

  These and further features and advantages of the present invention are set forth in greater detail, with the aid of the accompanying drawings, in the following description and in the claims, for purposes of illustration and not limitation.

1 is an exemplary diagram of a network for transporting communications and power according to some embodiments. FIG. FIG. 2 is an exemplary diagram of the network of FIG. 1 in which some principles of power distribution are shown. FIG. 2 is an exemplary diagram of the network of FIG. 1 in which some principles of optical communication are shown. FIG. 3 is an exemplary diagram of a first power distribution scenario according to some embodiments. FIG. 4 is an exemplary diagram of a second power distribution scenario according to some embodiments. FIG. 6 is an exemplary diagram of a third power distribution scenario according to some embodiments. FIG. 6 is an exemplary diagram of a fourth power distribution scenario according to some embodiments. FIG. 6 is an exemplary diagram of a fifth power distribution scenario according to some embodiments. FIG. 6 is an exemplary diagram of multiple connection configurations at a branching unit according to some embodiments. FIG. 4 is an exemplary diagram of a first scenario under a fault condition according to some embodiments. FIG. 11 is an exemplary diagram of a second scenario under the fault condition of FIG. 6 is an exemplary graph of the output voltage / current characteristics of a power supply when a fault condition causes a short circuit in the network, according to some embodiments.

  As already mentioned above, for example, the recent demand for communications and power in various industrial or scientific activities demands the possibility of providing networks with various underwater locations used by such activities. In this case, such a network can provide submarine users with a supply of optical connections at a low DC voltage (about 400V) and a relatively high bit rate. In addition, it is desirable for such a network to include equipment that can provide reliable service during long periods of operation in the range of about 25 years, where its components, more specifically wet (underwater). The need for equipment maintenance is kept to a minimum or at least reduced as much as possible.

  Network distribution is based on the principle of seawater return and the high voltage of about 10 KV DC present in the mains of the network, typically a lower voltage of about 400 V DC that can be used at the user wet-mate interface. A submarine node local medium voltage converter configured to convert to is used.

  The principle of seawater return relates to a configuration in which current flows through a single conductor cable and returns through the sea as a return conductor (electrodes in contact with seawater are provided at each node).

  This configuration may be particularly economical compared to known alternating current distributions that require at least two conductors in a single phase system or require three conductors in a three phase system.

  Converters for converting high voltages to voltages as described above are known in the related art.

  Such a network is optically amplified where repeaters can be used to re-amplify the optical signal at the appropriate distance so that the optical signal can reach the user's location located far from the shore. You may also use a trunk line. In such networks, dedicated wavelengths are distributed to user gateways (also referred to herein as nodes) so that end users are assigned to ensure reliable communication in a protected manner, or even A distributed DWDM optical scheme that can have a reserved capacity can optionally be used. Preferably, such a network is in the form of a ring network so that such allocated or reserved capacity is made available to users using both sides of the ring network. Also good. Preferably, the network provides the ability to electrically isolate the node from the rest of the network and minimizes the impact of such separation on other users of the network, such as in maintenance operations. A specific power switching device is further provided for the purpose of enabling specific local operation on a given node. Such a switching device may be incorporated in the branch unit.

  In addition, the network is able to implement specific IP switching within the network and nodes to enable implementation of functions related to the IP protocol, such as using the PTP protocol to distribute accurate timing to end users. Gear use may be provided. With such precise timing, synchronization of events in the network can occur with a high accuracy of, for example, approximately 5 to 10 microseconds, but other protocols such as NTP can have an accuracy of approximately 1 millisecond. It only becomes. The IP switch collates / distributes data coming to the user interface (typically 6 scientific ports each with 1 GigE) or destined for a composite 2.5 GBit / s upstream signal carried by one wavelength from there. Can be used in submarine nodes. Two 1 GigE signals may be mapped to STM-16 signals to build each wavelength.

  FIG. 1 is an exemplary diagram of a network 1 for transporting communication and power according to some embodiments. The network 1 comprises a terminal station 2 that may be typically located on the shore or fixed to the sea surface or may be a floating structure. In the example of FIG. 1, the terminal station 2 is shown to be on land (shore). An optical link cable 3, also called a trunk line in this specification, connects the terminal station 2 to a submarine device. One such subsea device may be a repeater 4. As is known, repeaters are used to re-amplify optical signals passing through optical cables. The repeaters 4 can be arranged at predetermined intervals (distances) to ensure such reamplification.

  The trunk cable 3 is configured to carry a high voltage DC power supply, for example, from about 1 KV to about 50 KV, and preferred power supply voltage values are about 15 KV, 12 KV and 10 KV (in the example embodiments shown herein) In which the latter is used) and is configured to carry an optical signal using one or more wavelengths. In some embodiments, the optical signal may be a wavelength division multiplexed (WDM), coarse density WDM (CWDM) or high density WDM (DWDM) signal. The optical signal can enable communication between the terminal station and the submarine location.

  The network 1 further comprises at least one branch unit 5. The branch unit 5 couples the trunk line 3 to the branch device by the branch line 51. According to some embodiments, the branch device may be a submarine node 6 that requires voltage supply and availability of communication with the terminal station 2. The submarine node may use a voltage substantially lower than the voltage present on the trunk 3 or may be provided at the output. For example, the DC voltage used or supplied by the submarine node can vary from 500V to 5V DC depending on the application and the voltage required for the low voltage device supplied by the submarine node. A preferred voltage value used or supplied by the submarine node may be about 400V (this value is used in the example embodiments shown herein).

  Typical low voltage devices referred to above can be communications equipment, instruments, sensors, electric engines, and the like.

  The submarine node 6 may further use optical communication using optical signals at a relatively high bit rate, eg, about 100 Mbit / s or higher. Some preferred bit rates are 1 Gbit / s and 10 Gbit / s.

  As shown in the figure, the network 1 may preferably be a ring network. This configuration provides optimized service availability because it can be transported in two directions along the ring. However, this is not essential and other network configurations, such as a single spur network, may also be used within the scope of the claimed invention.

  FIG. 2 is an exemplary diagram of the network of FIG. 1 in which some principles of power distribution are shown. In this figure, elements similar to those in FIG. 1 are given like reference numerals. In the example shown in FIG. 2, the terminal station 2 may include a power supply device that can supply a relatively high DC voltage of, for example, about 10 KV with different polarities.

  During operation, a supply voltage of about 10 KV, for example, may be applied to the main line 3.

  The power supplied to the trunk line 3 by the branch unit 5 may be branched to the submarine node 6 by the branch line 51. The submarine node 6 is configured to convert a high voltage of about 10 KV in this example to a lower voltage that can be used by the equipment at the corresponding location. In this example, the lower voltage may be about 400V. Some scenarios of power supply are described in further detail in connection with FIGS.

  FIG. 3 is an exemplary diagram of the network of FIG. 1 in which some principles of optical communication are shown. In this figure, elements similar to those in FIGS. 1 and 2 are given like reference numerals unless otherwise indicated in the figures. In the example illustrated in FIG. 3, the terminal station 2 may include a wired device that can transmit / receive optical wavelengths on / from the trunk line. Preferably, the wired device of the terminal station 2 may be capable of transmitting / receiving a multi-wavelength optical signal such as WDM, CWDM, DWDM or a type signal.

  In the example shown in FIG. 3, it is assumed that the terminal station 2 can transmit / receive a WDM type signal. As shown in the figure, the first terminal station 2a exchanges (transmits or receives) the first optical signal having the wavelength λx with the first submarine node 6a and the second optical signal λz with the second submarine node 6b. ) May be able to. Similarly, the second terminal 2b exchanges (transmits or receives) the third optical signal with the wavelength λy with the first submarine node 6a and the fourth optical signal λw with the second submarine node 6b. It may be possible. Submarine nodes 6, 6a and 6b may be equipped with transponders for the purpose of enabling reception and transmission of wavelengths.

  In operation, a multi-wavelength optical signal (with λw, λx, λy and λz among other possible wavelengths) provides different optical wavelengths to nodes 6a, 6b or other submarine nodes, for example with each terminal station 2a and 2b It may be given on the main line 3 by each source.

  If necessary, the repeater may be used to re-amplify the optical signal.

  In the branch unit 5a, the multi-wavelength optical signal having the wavelength λx is obtained from the main line 3 by optical coupling to the first submarine node 6a via the branch line 51a, for example. The submarine node 6a then filters the wavelength λx for use. This wavelength may be used for the purpose of enabling communication between the first submarine node 6a and the first terminal station 2a. Similarly, the optical signal having the wavelength λy is branched (added) from the first submarine node 6a to the trunk line 3 via the branch line 51a. This wavelength may be used for the purpose of enabling communication between the submarine node 6a and the second terminal station 2b.

  Similarly, using the branch unit 5b, the multi-wavelength optical signal having the wavelength λy is obtained from the main line 3 by optical coupling to the second submarine node 6b via the branch line 51b, for example. The submarine node 6b then filters the wavelength λy for use. This wavelength may be used for the purpose of enabling communication between the second submarine node 6b and the first terminal station 2a. Similarly, the optical signal having the wavelength λw is branched (added) from the second submarine node 6b to the trunk line 3 via the branch line 51b. This wavelength may be used for the purpose of enabling communication between the second submarine node 6b and the second terminal station 2b. Therefore, it is confirmed that a dedicated wavelength can be assigned for communication between the terminal station and the submarine node.

  Although not shown in the figure, it may also be possible to establish communication between the two end stations. If communication between two end stations is desired, it is sufficient to dedicate specific wavelengths between the two end stations, in which case such dedicated wavelengths are deleted at any intermediate submarine node. Without being transported over one optical cable from one terminal station to another. The technique of adding a wavelength to an optical cable or removing a wavelength from an optical cable may be any technique known to those skilled in the relevant art.

  With the above configuration, a simple and highly reliable communication function at a high bit rate is possible between any two communication points in the network as necessary.

  The power supply may be provided in various ways. By way of illustration and not limitation, several example scenarios are described below. Other scenarios may also be possible within the scope of the claimed invention.

  FIG. 4 is an exemplary diagram of a first power distribution scenario according to some embodiments. Specifically, the scenario shown in FIG. 4 relates to a single-ended mode of operation that can be considered a normal operating state (although two power sources are available in the network, such as terminal 2 in FIG. 1).

  The first power source PS1 is shown connected to the first cable head C1 of the trunk cable T, and the second power source PS2 is shown connected to the second cable head C2 of the trunk cable T. A pseudo load DL may also be provided in the circuit. The branch units BU1, BU2, BU3, and BU4 are provided at several locations along the trunk cable T. Each branch unit may be coupled to a respective submarine node N1, N2, N3 and N4. The trunk cable T is an optical cable that can transport electric power and optical signals.

  In this state (typically the normal state), both the power sources of PS1 and PS2 may be of negative polarity, for example, and PS1 provides DC power (voltage-current) on the cable head C1. As shown in the figure (also arrows on cable heads C1 and C2), the loop is closed between PS1 and the sea ground. On the other hand, the pseudo load DL is preferably present on the circuit to ensure current circulation in the same direction. To increase (or ensure) the availability of power on the system, PS2 may be connected in parallel with the pseudoload DL (to be incorporated into the circuit if PS1 fails). It may be in a standby mode. Preferably, the voltage of PS2 is adjusted to be lower than the voltage of the pseudo load DL. A diode may be used at the output of PS2 to prevent reverse current. Therefore, in this situation, PS2 does not supply any current.

  In the normal operation scenario of FIG. 4, submarine nodes N1, N2, N3, and N4 may be provided with current and optical signals for normal communication, if necessary. The direction of current flow is indicated by the arrows in the figure.

  When a failure occurs in the first power supply PS1, the second power supply PS2 can automatically take over the power supply operation of the system.

  FIG. 5 is an exemplary diagram of a power distribution scenario where the first power source PS1 is faulty (for some reason). In FIG. 5, elements similar to those in FIG. 4 are given like reference numerals. In such a case, PS1 is disconnected from the circuit and PS2 is automatically incorporated into the circuit to ensure current flow. Also, in the event of a failure in a node or trunk cable, the second power supply PS2 ensures current flow and allows for quick reconfiguration of one or more branch units. Thus, in this second scenario, service (power and communication) is also ensured for submarine nodes N1, N2, N3 and N4.

  As seen in the figure in the scenario of FIG. 5, the pseudo load DL is switched to another cable head, ie C1. Preferably, the switching of the pseudo load is performed during operation at nominal voltage, closing the switch to the cable head C1 in parallel with the switch to the cable head C2 (also closed) and then opening the switch for C2 (so-called Make-before-break switching (make-before-break switching) operation. The direction of current flow is indicated by the arrows in the figure.

  If the total power required exceeds the capacity of a single power supply, the trunk cable may be powered by both PS1 and PS2 power supplies, while the pseudo load is turned off (disconnected) Good. FIG. 6 is an exemplary diagram of a power distribution scenario under such circumstances. In FIG. 6, elements similar to those in FIGS. 4 and 5 are given the same reference numerals.

  The determination of whether two power supplies should be incorporated into the circuit may be obtained from a management system that may be located at the terminal station based on current and voltage monitoring. The management system may then set the current and voltage demands on power supplies PS1 and PS2 to keep the current equal in one of the nodes, eg N2 in the figure, so that any repeater is too low ( It is not necessary to receive a current (near zero). The reason for this concern is that repeaters are typically powered in series and power the laser pump and require a minimum current (several hundred milliamps) to ensure optical amplification. When power is received from both ends of a voltage of the same polarity (PS1 and PS2), the current flows in the reverse direction (as indicated by the arrows in FIG. 6) and there is always a point in the system where the current must flow backwards. . Therefore, at a given branch unit location where the power consumption (and hence the node current) is forced high enough to ensure that there is no portion where the current drops near zero between the two branch units. Causing current reversal, so that the current in this node is substantially half from one direction and half from the other direction (eg, if the node current is 1A, the power supply is 0.5A from one direction). (It may be set to 0.5A from other directions) It may be desirable to adjust the setting of the power supply to be received, this current also causes all other nodes to add current to the backbone to the land station Thus, it can be the minimum current in the entire system.

  Thus, this system has a node power that is too high for the system to operate with a single-ended supply (the far-end node has a voltage drop that corresponds to the cumulative drop of all other intermediate nodes) If there is a power limit that causes the system to collapse (when the node voltage is half the voltage of PS1), it may be set to double-ended supply (unless the pseudo load does not work).

  For this purpose, an algorithm may be used to adjust the DC voltage and current across the circuit (with a double-ended supply) and ensure a minimum current to all repeaters in the loop. Such an algorithm may be based on arithmetic operations using current measurements at node N2 where current balance is created (eg, using telemetry) and power supply equipment for determining current demand. Thus, one power supply may be set to voltage control mode and the other power supply may be responsible for current control to maintain the entire current. Assuming that the first power supply PS1 is in current mode, PS1 may have a current set to: I = I1 + I2 / 2. Therefore, another power supply in voltage mode carries the remaining current, i.e. I = I2 / 2 + I3 + I4.

  FIG. 7 is an exemplary diagram of a fourth power distribution scenario in which a double-ended supply is available when a trunk cable failure occurs. In FIG. 7, elements similar to those in FIGS. 4 to 6 are given similar reference numerals.

  Assuming that the trunk cable is under a fault condition as indicated by reference number F in FIG. 7 (eg, disconnecting the trunk cable may split the system into two separate circuits), each power supply PS1 and PS2 may be connected to the corresponding cable heads C1 and C2, and the pseudo load may be disconnected.

  In this particular scenario, the resistive load may be automatically connected to the input of a node near the cable fault. In such a case, the resistive load supports high voltage directly from the trunk. Alternatively, a resistive load may be connected to the output of the submarine node, in which case it supports a constant voltage on the branch. In FIG. 7, submarine nodes N2 and N4 are shown connected to respective resistive loads RL2 and RL4. The resistive load can ensure the presence of the minimum current required to operate the optical system and may be turned on automatically if optical communication is lost. If one of such submarine nodes N2 or N4 requires high power, the resistive load may be disconnected because it is typically a non-priority load. The direction of current flow is indicated by the arrows in the figure.

  In the scenario of FIG. 7 where the trunk cable is damaged by cutting, it may be necessary to reconfigure the entire system. In order to do so, the branch unit may have to receive certain commands. An exemplary solution for such a reconfiguration operation is shown in FIG. In this scenario, power supplies PS1 and PS2 are disconnected from the system. A third power supply PS3 that can operate in a reverse polarity power supply mode is incorporated to restore the DC current on the main line and allow communication within the system. This is done by reverse-biased diodes D2 and D4 at the input of the DC / DC converter inside the submarine nodes N2 and N4 (the node that was next to the cut point in FIG. 7). This current measure allows the system manager to send commands to branch units that need to be reconfigured (BU2 and BU4 in this example) and change the system topology as needed.

  The reconfiguration of the branch units is preferably carried out by means of optical monitoring signals that can be activated to change the connection configuration of the branch units. FIG. 9 is an exemplary diagram illustrating multiple connection configurations in a branching unit according to some embodiments. The figure shows four possible stable connection configurations. The first configuration AB provides a connection between ports A and B, and with respect to keeping port C open, the second configuration AC provides a connection between ports A and C, and port B With respect to opening, the third configuration BC provides a connection between ports B and C, and finally with respect to opening port A, the fourth configuration ABC consists of three ports A, B and Related to connecting C together. Note that two of ports A, B and C may be connected to the trunk line and the third may be connected to the branch line.

  In the event of a failure in a branch unit branch cable, the system may be configured to isolate the faulty cable and still keep the entire system available for servicing.

  Examples of types of branching units that can be used in the network of the present invention are described in US Pat. No. 6,987,902, which is incorporated herein by reference in its entirety.

  FIG. 10 is an exemplary diagram of a first scenario in which a failure is shown to occur at branch unit BU1. If such a fault is in the form of an open circuit, only one of the submarine nodes N1 is isolated from the system and the other submarine nodes remain operational, so the system may not suffer damage. However, if such a fault condition is in the form of a short circuit (as shown by node N1 in FIG. 10, the ports A, B and C of branch unit BU1 are all connected together), the system Is configured to automatically stop the conversion of the mains voltage from a high value (eg about 10 KV in normal state) to a lower value (eg about 500 V in normal state) at submarine nodes N2, N3 and N4 May be. Indeed, the converter at each submarine node may be configured to stop the conversion operation when the mains voltage falls below a predetermined threshold, eg, about 5 KV. In such a situation, the system is switched from the first power supply PS1 using a new voltage substantially lower than the predetermined threshold of the mains (5KV in this example) supplied by the power supplies PS1 and PS2. This is an end-to-end series connection circuit to the second power source PS2. The direction of current in the circuit is indicated by the arrows in FIG.

  FIG. 11 is an exemplary diagram of the second scenario under the fault condition of FIG. 10 that is adapted to resume after the system has cleared the fault at the branch line of branch unit 1. In the figure, elements similar to those in FIG. 10 are denoted by the same reference numerals. As shown in FIG. 11, the branch unit BU1 is reconfigured in a new state in which the ports A and B are connected together, so that connectivity on the trunk line T is possible. Since the short is now isolated from the circuit, the system may be resumed and the submarine nodes N2, N3 and N4 may be serviced. The direction of the current is indicated by an arrow in the figure.

  FIG. 12 is an exemplary graph of the output voltage / current characteristics of the power supply in the system in a fault condition caused by a short circuit in the network according to FIGS. In the figure, the X axis, that is, the horizontal axis, indicates the current limit in the main line, and the Y axis, that is, the vertical axis, indicates the voltage supplied by the power supplies PS1 and PS2. The objective is to maintain the current on the trunk line T at a safe low value when a short circuit as described with respect to FIG. 10 occurs in the branch line. As shown in the figure, in a normal state, the voltage that can be used on the main line is at an initial high value V1 (for example, about 10 KV). This is indicated by the reference number M in the figure. If the current increases (along the X axis) in the system, the voltage drops to an intermediate value V2. This is indicated by reference numeral N in the figure. The second voltage V2 can be established as the predetermined threshold described with respect to FIG. As the voltage drops below a predetermined voltage value V2, the submarine node stops converting, so the system functions as a series connection using power supplies PS1 and PS2 that provide safe low current. This is indicated by reference numeral O in the figure. Finally, as indicated by the reference number P in the figure, at a predetermined lower voltage V3, the system establishes a low current that is safe for system operation, thereby eliminating the point of failure and automatically reducing DC power. It is possible to switch the branch unit for restoration off to soft.

  Note that in the embodiment shown herein, two power sources PS1 and PS2 are described in an exemplary manner, but the network of the present invention is not necessarily limited to only two power sources. Indeed, additional power sources may be present in the network within the scope of the claimed invention. For example, the network may comprise an additional loop configured in a first ring (or parallel) network, or the network simply comprises a third supply with a three-branch network provided by a simple T-type connection. May be.

  If more than two power sources, such as N, are incorporated into the system, at least one power source is configured to control the voltage and the remaining N, similar to that described above with respect to the embodiment using two power sources. Based on the principle that the -1 power supply operates to control current, an algorithm may be used to manage the power supply.

  As mentioned above, the present invention provides a wide range of solutions for providing power and optical communications over a relatively wide range using commercially available submarine cables.

  The system proposed herein can serve a variety of applications such as, but not limited to, oil and gas scientific operations and deep sea detection operations.

  Because of the ability to use submarine communication devices such as cables, branching units and repeaters that are typically suitable for a design life of 25 years, this system, despite the fairly high line currents up to about 8A ( Provides a relatively long operational life (as compared to known systems that do not use such submarine communication devices).

  Elements such as power supplies, branch units, submarine elements and repeaters may include blocks that may be hardware devices, software modules, or a combination of hardware devices and software modules.

  Various embodiments of the invention may be combined as long as such combinations are interchangeable and / or complementary.

  Furthermore, it should be noted that the list of structures corresponding to the claimed method is not exhaustive, and those skilled in the art will enumerate equivalent structures without departing from the scope of the claimed invention. It will be understood that it can be replaced by a modified structure.

  Those skilled in the art will appreciate that any block diagram herein represents a conceptual diagram of an exemplary circuit embodying the principles of the present invention.

Claims (15)

  One or more terminal stations, which may be stations stationed on land, or fixed or floating at sea level, at least one branch unit, and at least connected to the branch unit A network for transporting communications and power comprising a single submarine node, the network enabling optical and electrical connections between the terminal station and the branch unit and between the branch unit and the submarine node A submarine node configured to receive a plurality of optical wavelengths and to provide at least one optical wavelength at the output, and to be provided with a first DC voltage received from the terminal station at the output. Configured to convert to a second DC voltage, the first voltage is higher than the second voltage, and the network is connected to the first cable head of the trunk cable A first power source and at least a second power source connected to a second cable head of the trunk cable, wherein the first power source and at least the second power source are individually under normal or fault conditions, Or a network configured in combination to provide at least a minimum amount of current in the network.   The network of claim 1, wherein the network comprises internet protocol switching means configured to implement an internet protocol application at the output of a submarine node.   The network according to claim 1, wherein the network is a ring network.   4. The network according to any one of claims 1 to 3, further comprising at least one pseudo load configured to allow current circulation.   The first power source is configured to supply direct current power to the first cable head such that the loop is closed between the first power source and the ocean ground, and at least the second power source is in standby mode 5. The network of claim 4, connected in parallel with the pseudo load.   The first power supply and at least the second power supply are configured to supply power, the first power supply is set to control voltage, and at least the second power supply is set to control current on the mains The network according to any one of claims 1 to 5, wherein:   The first power source is configured to supply power to the first cable head of the trunk cable, the second power source supplies power to the second cable head of the trunk cable, the pseudo load is disconnected, and the resistance load The network of claim 4, wherein the network is connected at a node close to the point of failure in the network to ensure the presence of current in the submarine node.   A third network is configured to provide a power supply so as to enable communication within the network as well as restore DC current on the trunk if a failure occurs on the trunk cable. The network of claim 7, comprising a power source.   The network comprises a management system configured to set a current demand and a voltage demand to a first power source and at least a second power source so as to keep current equal at least one node in the network. The network according to any one of 1 to 8.   The network of claim 1, wherein the submarine node is configured to stop converting the mains voltage from the first voltage value to the second voltage value if a failure occurs in the branch unit.   The network of claim 8, wherein the submarine node is configured to stop the conversion operation when the mains voltage falls below a predetermined threshold. One or more terminal stations, which may be stations stationed on land, or fixed or floating at sea level, at least one branch unit, and at least connected to the branch unit a method for feeding transportation communication and power within the network and a single submarine nodes, the network is, between the end stations and the branch unit, and the optical and electrical between the branching unit and the seabed node It is further equipped with a trunk cable to enable connection,
-Receiving a plurality of light wavelengths at a submarine node and providing at least one light wavelength at an output;
Converting the first DC voltage received from the terminal station into a second DC voltage provided at the output at the submarine node, the first voltage being higher than the second voltage; ,
The network comprises a first power source connected to the first cable head of the trunk cable and at least a second power source connected to the second cable head of the trunk cable, the first power source and the at least second A method wherein the power supply provides at least a minimum amount of current in the network, individually or in combination under normal or fault conditions.   13. The method of claim 12, wherein the submarine node obtains multiple optical wavelengths and filters the wavelengths for use at the submarine node, or the submarine node adds at least one wavelength to the trunk cable.   After the network further comprises a pseudo load, the switch to the second cable head is closed while the pseudo load is still switched to the first cable head, and the switch to the second cable head is performed, 13. Switching the simulated load from the first cable head to the second cable head by opening a switch to the first cable head so that the switching takes place at nominal voltage during operation. 14. The method according to any one of items 13. If the current in the network increases,
-Reducing the voltage available on the mains cable to an intermediate threshold value;
-Stopping the voltage conversion at the submarine node;
The method of any one of claims 12 to 14, wherein the step of providing a current lower than the increased current that allows one or more branch units to be safely switched off is performed. .

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